Crankshaft grinder



Nov. 21, 1950 RUTHERFORD I 2,531,161

CRANKSHAFT GRINDER Filed July 15, 1947 4 Sheets-Sheet l Har ry 775 a 777674721X Nov. 21, 1950 H. T. RUTHERFORD CRANKSHAFT GRINDER 4 Sheets-Sheet 2 Filed July 15, 1947 3. Harry 7: Pa ffie'rford.

4 Sheets-Sheet Nov. 21, 1950 Filed July 15, 1947 Nov. 21, 1950 H. T. RUTHERFORD CRANKSHAFT GRINDER 4 Sheets-Sheet 4 Filed July 15, 1947 Phi. 6.

Md i 6 M Q T Patented Nov. 21, 1950' CRANKSHAFT GRINDER Harry '1. Rutherfori Baltimore, MIL, assignor to Vickers, Incorporated, Detroit, Mich., a corporation, of. Michigan Application July 15, 1947, serialNo. 761,119

4 Claims.

The present invention relates to a portable crankshaft grinding tool and is in part a modified form of the grinding tool shown and described in my previously filed application. Serial Number 691,554.

Ingeneral the broad principles of the present form are the same as those in my prior application. However, there are certain features in the construction and operation in the present form of the tool which are new and novel in the art of. crank shaft grinders.

The-improvement consists principally in a tool that may, with a minimum amount of adjustment, be readily adapted to the grinding of crank shaft throw of various size shafts and engine blocks, one of the new features of the tool being to support the outer end of the tool by a plate or bracket adapted to be secured tothe block adja cent theouter-end of the cylinder. Another improved feature being in the grinding wheel positioning means, which is adapted to ride upon the bearing surface of the throw and is adjustable laterally in the direction of the axis of the shaft. These adjustable features will permit a considerable number of shaft bearings to be ground by a single machine without the necessity of interchanging parts.

The-primary object of the invention isto pro-- vide a grinding tool of increased efiiciency and adaptability over various size engines.

Another object of the invention is to provide an improved crank shaft engaging means in which. a maximum amount of clearance is provided between the shaft engaging means and the cylinder block when the crank shaft is rotated.

A: further object being to provide a machine in which the power unit is carried on the outer end of thetool.

Still another object of the invention is to provide a new and novel recoil mechanism for urging the tool in the direction of the cylinder as the inner end of the tool is moved about the path of the crank throw.

While several of the objects have been specificallypointed out, other objects will he more apparent as the invention is more fully described in the specification and shown in the acco1npanying drawings, in which:

Figure 1 is a view in elevation of one; foim of the assembled tool.

Figure 2 is an enlarged fragmentary sectional view of the member to which the guide means is pivotably attached.

Figure 3 is an enlarged fragmentary elevational: view ofthe crank shaft engagingrmeans- FigureA is a sideelevational view of thesame.

Figure, 5 is. atop plan view. of the roller cradle for providing a rolling contact with the crank shaft bearing.

Figure 6 is a view in elevation of amodified form of tool.

Figure 7 is'an elevational side view of the same.

Figure 8. is a fragmentary view in side eleva, tion of the form shown in Figural showing the tool. driving unit.

Referring to the drawings, the tool is provided with a rinding wheel 12 and a support iii there-- for. The-support is formed with the portion It extending outwardly from one side of. the wheel for supporting the grinding wheel and the drive shaft 15. The bracket in ispreierahly utilized to form, an arcuate bracketcr crank shaft engaging element, as shown at I0, which is adapted to extend around a portion. of the bearing surface M'of the crank shaft I3. Adjacent the-extended end, of the bracket is the portion I9 which is provided. with a slot !8 which is in. a plane substantially parallel with the of the rotating grinding wheel. For supporting and aligning the tool upon the crank shaft there is a cradle I6 having a portion [6 whichis adapted to slidably fit within the slot 18.

Located substantially centrally. of. the arcuate bracket is an adjustable roller Iii which may be adjusted to contact the shaft bearing by moving the pin 2|, upon which the roller is mounted,

through appropriate aperture within the por-- tion H1 where it may be secured in position by the screw. 21.

The cradle I5 is providedwith rollers 2.4, 554, 26 and 26 which are mounted upon the outer ends of the shafts 28, 29, 30 and 3 1 respectively. These wheel supporting shaftsare carrie in two parallel apertures 32 and 33 running alongthe ends of the cradle. Each shaft is adapted to occupy approximately one-half the length of the aperture. The outer edges of the apertures are slotted at 34 and 36 and will act as a clamp for securing the shaft members in place. The clamping'acti'on is regulated by the screws 42 and M. This arrangement is for adjusting the wheels laterally in order to extend the wheels to a point adjacent the outer edge of the crank. shaft ing surface l4. In order to adjust the whe the screw members 42 and 44 are loosened the shaft members upon which the rol ers are mounted maybe moved in any desirable location and fixably secured by tightening. the screws 42 and 44. The portion 16- of the cradle being slid ably: receivable within the slot in isalsofixebly:

adjustable within the slot. Located substantially centrally of the portion iii" is a screw which is adapted to abut against the outer edge of the portion It of the cradle. There is a pin 2 3' extending outwardly from the portion 28 of the screw for engaging an aperture It within the cradle to prevent the cradle from moving longitudinally of the slot.

The pitch of the thread 28 of the screw 29 is such that when the screw is rotated through the distance of one graduation, as shown at 23, on the knob 23, the cradle is moved onethousandth of an inch. The screw 28 is normally held against rotation by the spring member 21. By providing these narrow gauged wheels, which are adjustable to operate adjacent the outer edge of the bearing, a more even running surface is obtained as this portion of the bearing generally receives less wear and abuse than the central portion. The outer edge of the rims of the wheel are also slightly beveled to conform to the fillet which is present in most crankshaft earings.

The grinding wheel is mounted in such a manner that its grinding surface is rotated in a plane H parallel with the axis of the crankshaft bearing and is of substantially the same width as the crankshaft bearing surface. The wheel is preferably offset slightly in the direction of the opening formed by the arcuate member It. By offsetting the wheel the entire surface of the bearing including the fillet may be efiiciently and neatly ground with the hat face of the wheel, and if offset in this particular direction, a greater clearance is obtained between the member If) and the inner portion of the cylinder block as the tool is operated by the turning of the crankshaft l3.

Positioned upwardly from the wheel and drive shaft support It is a yoke member 46, the support member if! and the yoke being connected by the member 48. By this arrangement the distance between the yoke member and the support If! may be adjusted by the screws 58 and 5E. The outer end of the yoke is provided with arbors 52 and 54 extending outwardly from each side thereof. These arbors are provided with apertures 52 and 54'. Within these apertures are provided trunnion members and 58. These trunnions are h ld in place by the screws 59 and 69. The outer central portion of the yoke is cut away to a point substantially along the axis of the trunnions. The yoke is provided with a central aperture 22 through which the drive shaft i5 is carried. Adjacent the yoke and extending a substantial distance upwardly therefrom there is provided an elastic covering 66 for snubbing the bending action of the flexible drive shaft l5. The opposite end of the drive shaft :5 is connected with any suitable form of power unit for driving the shaft and rotating the grinding wheel. The driving unit i243, as shown in Figure 8, is in the form of an electric motor and is mounted to the plate 1'2 by the arm l2l.

For supporting and positioning the outer end of the tool there is provided guide means 58 which are adapted to be guided along a predetermined path by passing through the aperture 18, or other suitable means, carried by a plate or bracket member '22. The inner end of the guide means is provided with portions 13 and 14. These portions are provided with apertures i5 and 16 which are adapted to fit over the trunnions 56 and 58 of the yoke member. Extending outward- 1y between the plate 12 and collars 80 are spring 4 members 8! for urging the yoke and tool toward the outer end of the cylinder 82 of the engine block 84. The plate, or bracket, 12 is held upon the engine block by the clamps 86 and 88 by the nuts 90 and BI.

Referring to Figures 6 and '7, the tool is shown as having the power unit I08 mounted upon the upper extremities of the guide means 88 by a bracket Hi2. The bracket is secured to the guide means in any well-known manner. The outer end of the drive shaft I5 is equipped with a coupling I04 which is adapted to slide along the power unit shaft HS. Within the coupling is a slot I86. Fixably receivable within the shaft H0 is a pin I08 which is adapted to slide within the slot I65. This is to provide for end movement between the flexible drive shaft l5 and the power unit as may occur when the tool is being operated.

To place the tool in operation, the inner end of the tool, which includes the bracket portion l8 and the cradle I6, is inserted through the outer end of the cylinder until the plate 12 comes in contact with the outer face of the block. At this point the lower part of the tool, including the grinding wheel and the bracket Hi, will be suspended from the guide means 68, which are in turn held outwardly by the compression springs 8!. The tool is moved inwardly against the force of the springs 8|. The cradle 16, carried by the arcuate'bracket i8, is moved into place on the far side of the crankshaft throw bearing and so adjusted that the grinding wheel will be out of contact with the shaft until the actual grinding process is to begin. Likewise, the plate '12 is fastened in place by the clamps 86 and 88.

After the tool has been clamped into operating position, the crankshaft is slowly turned at a speed of approximately 10 revolutions per minute by any convenient method, preferably by an electric motor (not shown) having the proper reduction gears, which may be connected to the fan belt wheel adjacent the front end of the crankshaft. As the crankshaft is rotated, the tool will be carried around the crankshaft and occupy substantially the same space and area as do the connecting rod and piston when in normal operation of the engine. After the crankshaft has begun to rotate, the grinding wheel, which may now be started or may already be in motion, is brought in contact with the shaft by adjusting the screw 29 which moves the tool inwardly toward the shaft bearing by moving the cradle toward the wheel. The tool, throughout the grinding operation, is held outwardly toward the outer end of the cylinder by the springs 8| which keeps the cradle in constant contact with the far side of the crankshaft. This makes the adjusting of the grinding wheel upon the shaft a very simple matter as it is only necessary to move the cradle upwardly out of the slot I8 by operating the screw 20.

While a preferred form of the invention has been described in detail, it is to be understood that the invention is not to be limited to this specific structure as the scope of the invention will be best defined in the appending claims.

I claim:

1. A throw bearing surface grinding tool for an assembled crank shaft and engine cylinder block comprising a grinding wheel and a drive shaft therefor, supporting means for said wheel and drive shaft having a portion thereof extending outwardly from one side of the said wheel to receive one end of the said drive shaft, said shaft extending through the cylinder area of the block for rotating the said wheel in a plane parallel with the axis of the crank shaft hearing, tool positioning means adjacent the outer end of the tool consisting of reciprocatory guide means pivotably connected with the said wheel support at a point within the cylinder, and a bracket adapted to be fixably secured to the block adjacent the outer end of the cylinder, said bracket having means for directing the said guide means along a predetermined path, means for urging the said tool toward the outer end of the cylinder, positioning means adjacent the opposite end of the tool for engaging the crank shaft and having means associated therewith for supporting the wheel in proper grinding relationship with the said shaft as the same is rotated.

2. A throw bearing grinder for assembled crank shaft and engine cylinder blocks comprising a grinding wheel, supporting means for said wheel having a portion thereof extending outwardly from one side of the said wheel to receive one end of a drive shaft, said drive shaft adapted to be extended through the cylinder area of the block, for rotating the said wheel in a plane parallel with the axis of the crank shaft bearing, positioning means adjacent the outer end of the tool consisting of reciprocatory guide means pivotably connected with the said wheel support and a bracket adapted to be fixably secured to the block adjacent the outer end of the cylinder, said bracket having means for directing the said guide means along a predetermined path, power means carried by the said guide means for operating the said drive shaft, means operating between the guide and bracket for urging the tool toward the outer end of the cylinder, positioning means adjacent the opposite end of the tool for engaging the crank shaft and having means associated therewith for supporting the wheel in proper grinding relationship with the said shaft as the same is rotated.

3. A throw bearing grinder for assembled crank shaft and engine cylinder blocks comprising a grinding wheel and a drive shaft therefor, supporting means for said wheel and shaft having a portion thereof extending outwardly from one side of the said wheel to receive one end of the said drive shaft, said drive shaft extending through the cylinder area of the block for rotating the wheel in a plane parallel with the axis volved.

of the crank shaft bearing, positioning means adjacent the outer end of the tool adapted to be secured to the block adjacent the outer end of the cylinder, a bracket associated with the grinding wheel support and extending around at least a part of the crank shaft, a cradle carried by said bracket and adapted to be positioned on the opposite side of the shaft from the grinding wheel, a plurality of supporting rollers carried by said cradle for contacting the surface of the crank shaft bearing, means for laterally adjusting the said rollers and means for adjusting the said bracket relative to the said grinding wheel for moving the said wheel in contact with the said crank shaft bearing.

4. A power tool for grinding the throws of an engine crank shaft while positioned in the engine, comprising a member engageable with the shaft throw and having a bearing for a grinding wheel shaft extending perpendicularly to the crank shaft and on the side thereof towardthe engine cylinder, a grinding wheel shaft mounted in the bearing and carrying a grinding wheel with its flat end face tangent to the surface of the crank shaft throw, means extending into the engine cylinder for driving the grinding wheel shaft, means engaging the head face of the engine having longitudinal guide ways parallel to the cylinder axis, tool supporting means slidable in said guide ways and a pivot joint connecting the tool supporting means with the grinding wheel shaft bearing whereby the grinding wheel may be guided with its working face adjacent a crank throw and maintained constantly parallel to the crank axis while the crank shaft is re- HARRY T. RUTHERFORD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,151,139 Morris Mar. 21, 1939 2,247,344 Fuglie et a1. June 24, 1941 2,277,144 Petersen Mar. 24, 1942 2,447,117 Emory Aug. 17, 1948 FOREIGN PATENTS Number Country Date 254,259 Germany Nov. 28, 1912 408,673 Great Britain Apr. 16, 1934 

